If you’re quick (posted for a week or so), the NYTimes has some important history of the how the demonstrations against the Danish cartoon publication built:
At Mecca Meeting, Cartoon Outrage Crystallized – New York Times
This fills in some of the details of how the publication of a set of cartoons in September lead to riots in February. A big part of the picture is the refusal of Danish goverment officials to meet with concerned Moslem representatives. This is added to the general feeling on the “arab street” that West is out to get Islam (keyed by the Iraq invasion) leading to electoral victories in many countries by Islamist and by Hamas in Palestine which in turn put pressure on moderate politicians.